Chapter 5 Flashcards
Define concentration, and concentration gradient.
Concentration- the number of molecules divided by volume
Concentration Gradient- an increase or decrease in the concentration of a chemical substance within a given region
Draw a plasma membrane with all components discussed in class (phospholipids,
channel proteins, glycoproteins/glycolipids, receptor proteins, cholesterol). Describe the
function of components. How do the different membrane components move things in
and out of the cell?
-A lipid (fat) that contains phosphorus. Phospholipids are a major part of cell membranes (acts as a barrier)
-A channel protein, a type of transport protein, acts like a pore in the membrane that lets water molecules or small ions through quickly.
-These proteins have active sites shaped to fit specific signal molecules, such as hormones.
-Blood cholesterol is a waxy, fat-like substance made by your liver
-Glycoproteins, glycolipids, and proteoglycans on cell surfaces play critical roles in cell-cell recognition and the formation of tissues
Describe osmosis? Describe a situation where osmosis occurs?
-Water moves freely across the cell membrane
-Many other molecules dissolved in water cannot move through the membrane
-Water will passively diffuse across a selectively permeable membrane from where water is crowded to where water is less crowded
-Water diffusing through a membrane
-Osmosis DOES NOT involve the movement of solutes
-The ability of an extracellular solution to make water move into or out of a cell by osmosis is known as tonicity
-Water always moves into the hypertonic solution
EX: if you put a potato into pure water, it swells up over time. This is because there’s a much higher concentration of starch and other solutes inside the potato’s cells than in the water, so water flows into the potato cells by osmosis
What is the function of signaling molecules and their receptors?
Describe endocytosis
Endocytosis is a process in which a cell takes in materials from the outside by engulfing and fusing them with its plasma membrane
Define hypertonic, hypotonic, isotonic.
Hypertonic- high solute concentration
Hypotonic- low solute concentration
Isotonic- equal solute concentration
Define terms discussed in class
Draw a cell with more solutes inside the cell compared to the solution the cell is bathed in. Is the cell hypotonic or hypertonic to the surround solution? Is the solution hypotonic or hypertonic to the cell? In which direction will water move? What is the term to describe the movement of water?
on paper
What are similarities and differences between simple diffusion, facilitated and active transport?
Simple and facilitated move from high crowded areas to less crowded.
simple diffusion
-where molecules move from a highly crowded area to a less crowded area.
-The cell DOES NOT have to spend energy to have molecules move this way
facilitated diffusion
-Molecules move from a highly crowded area to a less crowded area but must pass through a protein channel to cross the cell membrane
-NO energy needed
active transport
-Molecules move from less crowded areas to more crowded areas
-Requires a carrier protein and the spending of energy
-Energy IS needed
osmosis
the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell’s partially permeable membrane.
define exocytosis
Exocytosis is a form of bulk transport during which large numbers of molecules are transported out of the cell.
